Synthetic diamond can be epitaxially grown by chemical vapor deposition on a pre-existing diamond substrate. However, the availability of seed crystals limits the maximum diamond film dimensions to a few millimeters on a side. A larger, effective diamond seed size can be made by placing a number of smaller diamond seeds within a few to 10 microns of each other in a tiling or mosaicing process. Film growth will begin on each seed individually but the film will grow laterally as well as vertically and eventually the films will grow together to form a continuous film of large dimension.
Current attempts at forming a mosaic of seed crystals have concentrated on forming a thin layer of diamond of less than 1 micron thick obtained from the bulk seed crystals and then mosaicing a suitable substrate with these thin seeds. However, the seeds used in the mosaic are only useful for one film growth since the seeds are incorporated into the film.
The use of thin and thick diamond crystals, or a diamond for any purpose, is too expensive whether the diamond is natural or synthetic.